fossil

Fossilized wood (petrified wood)

Silicified fossil wood; commonly quartz/chalcedony (SiO₂) replacing wood

AI-generated identification · may be incorrect

Usually Mohs hardness 6.5–7, earthy to subvitreous luster, brown/gray coloration, and preserved fibrous or woody grain. The image’s elongated, weathered form is consistent with fossil wood, though exact identification requires a close examination of cellular structure and density.

Identified September 11, 2026More fossil →

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Physical properties

Formation & geological history

Buried wood was mineralized as silica-rich groundwater replaced or filled its tissues, commonly during the Cenozoic or older sedimentary deposits. It occurs in volcanic ash beds, river sediments, and petrified forests.

Uses & applications

Used as decorative stone, bookends, carvings, cabochons, and collector specimens; high-quality patterned pieces are polished for jewelry and display.

Geological facts

Unlike ordinary wood, true petrified wood is stone-like and generally does not retain organic material. Silica may occur as quartz, chalcedony, or opal, producing varied colors from trace iron, manganese, and other elements.

Field identification & locations

Identify it by visible wood grain, cellular patterns, stone-like weight, and inability to bend or splinter; a streak and hardness test can help, but avoid damaging specimens. Common localities include Arizona, Wyoming, Madagascar, Indonesia, and Australia.